I. Field of the Invention
The present invention relates generally to ladders, and more particularly to modular ladder systems for climbing trees.
II. Description of Prior Art
In the sport of hunting, especially when the quarry is deer, the use of a treestand is a very common practice. The treestand offers many advantages, such as enabling the hunter to view his surroundings from an elevated vantage point, and minimizing the chances of being spotted or smelled by the deer. Therefore, development of treestand technology to facilitate the achievement of these objectives has been quite progressive, focusing on both portability and adaptability. Despite the advances made in this filed, however, there still remains the problem of actually climbing the tree to set up the treestand, and a number of prior techniques have been attempted with varying levels of success. Several of these devices are explained below, and each one offers the hunter a unique balance of portability, strength, stability and adaptability to the tree-climbing environment.
The simplest ladder known in the prior art, other than simply using the branches of the tree, is the conventional ladder having two parallel members connected by perpendicular rungs. Whether such a ladder has a unitary construction or is an extension ladder, it is extremely cumbersome for carrying through dense woods and is oftentimes quite heavy. Also, such ladders are necessarily straight and may not be well suited for use with a tree having an irregular shape. Finally, under the adverse conditions presented by most hunting environments, a conventional ladder is typically unstable and dangerous.
To overcome the problem of portability associated with conventional ladders, a number of alternative designs have been attempted. Some devices simply include two or more sections or modules of conventional ladder design which connect end-to-end, and the resulting assembly is tied to the tree to improve stability. While these designs made headway in improving portability, they remain ill-suited for use with trees having an irregular axis or many low branches which interfere with the long straight-line distance that the ladder is meant to span.
Another alternative design also comprises a number of connected modules, where each module has a single vertical member from which several steps are placed perpendicularly thereto. Some models have the steps offset from one another, such as in the case of the "Po-Jo Climbing Pole" manufactured by Amacker International, Inc., in Delhi, La. In other models, the steps are formed in a continuing T-configuration with respect to the vertical member, as seen in the "Sky Ladder" manufactured by Loc-On Company in Greensboro, N.C. The assembled ladder is then either tied to the tree with a rope or strap, or attached to the tree by a set of metal tongs. One of the advantages of such devices are that they are more lightweight than those ladders employing parallel vertical members. In those ladders where the steps are arranged in a continuing T-configuration, another purported advantage is that the climber is afforded the ability to place both feet on the same level while climbing, resulting in a more comfortable and stable climb.
Despite their apparent advantages, none of the above devices have addressed the problem of trees which have: (1) so-called "bell bottoms", or unusually wide trunks, such as cypress and tupelo trees typical in the southern United States; (2) a main vertical axis which is very irregular; or (3) many low-level branches which do not allow for a continuous ladder spanning a large distance to the treestand.
However, the ladder modules marketed under the trademark "Speed Steps" by Alumitech Industries, Inc., in Mamou, La., are an attempt to overcome those unique concerns. That ladder system is essentially a number of mini-ladders of conventional design which are separately attachable to the tree, except that the tips of the parallel rails at both ends are curved toward the tree to provide a four-point contact. While it is an improvement over prior devices to some extent, several weaknesses are apparent. First, the double-rail design does not allow the climber to place both feet on the same level at some point on the module, and is somewhat bulky when carried with other modules. Second, the modules are not internally adjustable in any way, so they cannot make maximum use of the existing tree structure, and they cannot be made more compact for storage and transportation. What is needed, therefore, is a modular tree ladder system which is conveniently portable, strong, stable, and adaptable to a variety of tree climbing environments.